1. Field of the Invention
The present invention relates to an integrated type transformer, and more particularly, to an integrated type transformer that reduces the volume by integrating a plurality of transformers transmitting power for driving a plurality of lamps in an inverter circuit for an LCD into one transformer structure.
2. Description of the Related Art
In recent years, liquid crystal display (LCD) products, such as LCD TVs or LCD monitors, have become larger. At the same time, however, there has been a need for a decrease in volume of the large LCD products. In order to satisfy the need, development has been carried out to realize small and compact built-in circuits and components that are used in the LCD products. This trend is also found in driving circuits, which are one of the main circuits in the LCD products.
The above-described LCD driving circuit generally uses a power conversion transformer to supply a current to a plurality of lamps. According to a general method of making the LCD driving circuit smaller, the volume of the transformer that supplies the current to the lamps is decreased.
FIG. 1A is a plan view illustrating a transformer according to the related art.
Referring to FIG. 1A, the transformer according to the related art includes a bobbin B that has a plurality of winding sections, and a core Co that is electromagnetically coupled to the bobbin B.
A primary coil C1 is wound around the center winding section. Secondary coils C2 are separately wound around both winding sections around the center winding section. The core Co that is coupled to the bobbin B surrounds the inside of the bobbin B and the bobbin B in a longitudinal direction thereof to form two magnetic paths, which will be described in detail with reference to FIG. 1B.
FIG. 1B is a cross-sectional view illustrating the transformer taken along the line a-a′ according to the related art.
Referring to FIG. 1B, the core Co that is coupled to the bobbin B includes an inner core Coi that is inserted into the inside Bi of the bobbin, and outer cores Coo1 and Coo2 that are formed along two surfaces that face each other among outer circumferential surfaces of the bobbin B. The inner core Coi is electromagnetically coupled to the external cores Coo1 and Coo2 to form magnetic paths, that is, two magnetic paths. The current that flows into the primary coil C1 is converted into AC power, which is set beforehand, and then transmitted to the lamps (not shown) by the secondary coils C2.
In the transformer according to the related art, a plurality of transformers are integrated into one transformer structure. However, since the volume of the transformer is still large, it is difficult to manufacture a small, thin, lightweight driving circuit that uses the transformer.